JPS6390631A - Fuel injection pump for internal combustion engine - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a fuel injection pump for an internal combustion engine, which includes a delivery amount adjusting member that adjusts the amount of fuel delivered, and a speed regulating mechanism that operates the delivery amount adjusting member. The speed regulating mechanism has a lever mechanism consisting of an adjusting lever connected to a delivery amount adjusting member, and a lever supported on the same axis as the adjusting lever and carrying the adjusting lever, and the above-mentioned Reno ζ-mechanism is loaded on the one hand by an adjusting spring serving as a guide for the rotational speed of the internal combustion engine and an idling spring fixedly arranged relative to the casing, which adjusts the idling speed, and on the other hand, It relates to a type that receives load from a centrifugal governor. In a fuel injection pump of the above-mentioned type known from DE 35 00 341 A1, the idling spring, which is arranged at one end in a stationary and adjustable manner in the housing, is loaded by a stronger spring, the adjusting spring. The start lever is selectively actuated on the pulley 7, or on the start lever loaded by the centrifugal auxiliary machine, and the start lever is also connected as an adjustment lever to the delivery amount adjustment member. Since the adjusting force exerted by the adjusting spring and the centrifugal governor in relation to the rotational speed significantly exceeds the adjusting force of the idling spring, it is precisely during idling operation that the rotational speed should be kept at a relatively low speed. The non-uniformity (P-degree) of the change in the delivery amount over the range increases, resulting in a difference in the characteristic values that define the idling speed.

has a relatively strong influence on the height of the eye rotation speed.

In contrast, in the fuel injection pump of the present invention having the feature set forth in claim 1, the points of application of the adjustment force of the idling spring and the points of application of the adjustment forces of the adjustment spring and the centrifugal governor are separate. It is separated into a lever, in which case the idling spring acts on a final adjustment lever, which is adjusted with a relatively low force for the output quantity adjustment element.

With this configuration, an idling spring with soft spring characteristics can be used. Furthermore, the idling spring, which is arranged stationary with respect to the housing at one end, can be adjusted relatively easily, so that the idling speed can be adjusted in a simple manner. Moreover, since it is adjusted over the idling speed and no force fluctuations occur, a stable fuel delivery process is achieved during full load operation.

Based on the fact that the adjustment lever is merely loaded with the spring force of the idling spring in the direction of increasing the delivery amount, by configuring the entire injection pump as described in claim 3. , an adjustable stopper for modifying the fuel delivery rate at full load, in relation to atmospheric air pressure, filling pressure, temperature or other operating parameters, thus requiring only small adjustment forces; can be actuated by a small regulating device.

Further, as described in claim 5, the adjustment lever is connected to the shock absorbing device, thereby preventing the vehicle from being subjected to sudden yaws in the event of a sudden load change.

The invention will now be fully described with reference to the illustrated embodiment.

According to the illustrated embodiment, the casing 1 of the fuel injection pump
A pump plunger 3 is actuated in the slider/daper hole 2, and the pump plunger 3 simultaneously performs reciprocating motion and rotational motion by a drive mechanism (not shown). The pump working chamber 4 of this pump unit is constructed by a longitudinal groove 5 arranged on the face of the pump plunger and a suction chamber (
Fuel is supplied from the injection pump inner chamber]7. During the discharge stroke of the pump plunger 3, fuel is delivered from the pump working chamber 4 into a vertical passage 8 passing through the pump plunger 3;
From here, the fuel is conducted via the entire distribution flute 10 into one of the delivery channels 11, depending on the rotational position of the pump plunger 3. The number of delivery channels 11 is equal to the number of cylinders of the internal combustion engine, and these delivery channels 11 are arranged distributed around the cylinder bore 2 .

An annular slider 16 as a delivery amount adjusting member is movably supported on the pump plunger 3, and this annular slider has one radial hole 17 communicating with the vertical passage 8.
During the course of the delivery stroke of the piston syringe 3, the opening of the radial bore 17 is finally opened and the pump working chamber 4 communicates with the suction chamber 7, so that from the point of this communication on the pump plunger The remaining fuel pushed out from 3 is no longer supplied to the delivery passage 11. Therefore, in the discharge stroke of the pump plunger 3, depending on the position of the annular slider 16, the pump working chamber 4 is communicated with the suction chamber 7 after a different stroke distance of the pump plunger in each case, and the fuel delivery is interrupted. . The more the annular slider 16 moves in the direction of the top dead center of the pump plunger 3, the greater the amount of fuel delivered from the pump plunger to the delivery passage 11 and further to the fuel injection nozzle (not shown). do.

The annular slider 16 is adjusted by a two-armed adjustment lever 18 or a metering lever ζ, which is pivotable about the axis 19 and which, via a head 20i at one end, opens a notch in the annular slider 16. 21.

For adjustment, the shaft 19 can be moved approximately parallel to the axis of the pump plunger 3. For this purpose, the shaft 19 is arranged on an adjusting rocker 12 which is pivotably mounted in the housing 1 and is held in position by a compression spring 13 and an adjusting screw 14.

Furthermore, there is a single-arm lever 22! It is possible to turn around 11119. An adjustment spring 24 acts on this lever 22 after a predetermined no-load stroke, and one end of this spring
It is latched onto an adjusting lever 25, and its other end passes through a hole 26 in the outer end of the lever 22 and has a stop disk 27. The adjusting sleeve 29 of the centrifugal governor 30 acts on the reno Z-22 in a direction opposite to the direction of action of the adjusting spring 24. The centrifugal speed governor 30 is driven by a transmission mechanism (not shown) in accordance with the rotational speed of the pump plunger drive mechanism.

The centrifugal governor 30 has a plurality of centrifugal weights 33 in a centrifugal governor casing 32, and these centrifugal weights are movable longitudinally on a shaft 35 by a protrusion 34' (il-). It acts by engaging the lower edge of the supported adjustment sleeve 29.

The stopper 36, which is immovable with respect to the casing, is the centrifugal governor 3.
The pivoting movement of the lever 22 in the direction towards zero is restricted.

The second arm 40 of the adjustment lever 18 extends alongside the lever 22. The second arm 40 has a stopper 41 facing the lever 22, and this stopper has a distance al from the lever 22 when the fuel injection pump is stopped. The end of the arm 40 is divided into two branches 42,43. An idling spring 44 is suspended from one branch 42, and this idling spring is weaker than the adjustment spring 24. The other end of the idling spring 44 is an adjustment lever 45
This adjusting lever is rotatably and fixedly supported on the casing 1, and the idling speed is adjusted by means of this adjusting lever.

In the pivoting movement path of the adjusting lever 18, it also
An adjustable stop 46 extends into the area of the branch 43, which limits the pivoting movement of the adjusting lever 18 in the direction of increasing the fuel delivery of the pump unit.

The stop 46 is connected to a pneumatic, hydraulic or electric regulating device 47, which is known per se, and which adjusts various operating parameters of the internal combustion engine, e.g. It is controlled in relation to atmospheric air pressure, filling pressure, temperature, etc. In the embodiment according to FIG. 1, the stop 46 is part of a fork 48 on the adjusting rod 49 of the adjusting drive 47, in which a compression spring 5 is provided to compensate for all the play.
9 presses the branch 43 against the stop 46, the stop 46 is moved by the adjusting drive 47 in each case in line with the required correction amount of the fuel delivery quantity, i.e. the pivoting movement of the adjusting lever 18 and thus also It is moved to a position that limits the delivery amount to varying degrees.

In addition to the adjustable stop 46 , a damping device 50 can additionally be connected via a rod 57 to the second branch 43 of the arm 40 of the adjusting lever 18 .
Adjust? -18 sudden adjustment movements are prevented. The shock absorber 50 has a piston 52 in a cylinder 51 through which a rod 57 passes, a head 53 at the free end of the rod 57 and a compression spring 54 supported on the branch 43. is restrained between. piston 5
2 is loaded with the pressure of fuel in the suction chamber 7,
On the other side, via a throttle passage 55 in this piston 52 and a reverse valve 56 that blocks the throttle passage 55 in one direction,
It is connected to the suction chamber 7. Due to the piston 52 and the non-return valve 56 being flexibly stopped in one direction, the damping device 50 is only effective in one direction, so that when the rod 57 is moved in one direction, the rapid movement of the piston 52 is prevented. In the opposite direction, the piston moves slowly and slowly. Additionally, instead of the above-mentioned damping device 50, which only acts in one direction, it is also possible, if desired, to provide a damping device, which is known per se, and which acts in two directions. .

In certain installation positions of the injection pump or in the case of high acceleration forces, it may be necessary to increase the holding force of the adjusting lever 18 completely. For this purpose, the adjusting sleeve 29 of the centrifugal governor 30 is loaded with a compression spring 31, which is connected to the shoulder 37 of the shoulder 35 and to the step 38 of the adjusting sleeve 29.
It is supported between. If a compression spring 31 is arranged, the strength of the idling spring 44 must also be correspondingly increased.

The operating mode of the fuel injection pump regulating device described above is as follows.

At the time of startup, the annular slider 16 as a delivery amount adjusting member
The adjusting device is in the position shown in FIG. In this case, the lever 22 rests against the adjusting sleeve 29 of the far 2L governor 30 and is stopped at a distance from the adjusting spring 24, so that the lever 22 is at a predetermined distance 1) relative to its stop disk 27. have,
And it has a distance a from the stopper 41 of the adjustment lever 18. The adjusting lever 18 is held by an idle spring 44 in a position in which the annular slide 16 assumes its highest position. At this highest position of the slider 16, the fuel injection amount is maximum. After starting, the adjusting sleeve 29 is moved as the rotational speed increases, so that the lever 22 comes into contact with the stop 41 of the adjusting lever 18. If the rotational speed increases further, the idle spring 44 acting on the adjusting lever 18 adjusts. This idle spring balances the force exerted by the centrifugal 14-speed machine 30, in which case the annular slide 16 is held in a position that defines the entire idle speed. When the rotational speed exceeds the idling range, the distance of the lever 22 relative to the stop disc 27 disappears completely, so that the lever 22 rests against the stop disc 27 of the adjusting spring 24. In order to increase the speed during part-load or full-load operation of the internal combustion engine, the adjustment spring 24 is tensioned via the speed adjustment lever 25, so that the lever 22 is activated by the centrifugal governor 30. Let's turn against it.

I can't stand it.

If the position of the rotation speed adjustment lever 25 is suddenly changed by the driver, or if the load changes suddenly and the force of the centrifugal governor changes accordingly, the position of the lever 22 will be changed suddenly. On the other hand, the position of the end lever 18 connected to the shock absorber 50 is changed with a certain time delay, and as a result, the injection amount is also changed with a delay. Due to the damping device 50, which acts only in one direction, the adjusting lever 18 is quickly adjusted by the lever 22 in the event of a sudden change in the rotational speed of the centrifugal governor 30. That is, the rod 57 connected to the adjustment lever 18
The head 53 of the piston 5 resists the action of the compression spring 54.
2, in which case the adjusting lever 18 adjusts the annular slide 16 to a position which results in a somewhat lower fuel injection quantity. On the other hand, the aperture hole 5
The shock absorber @ 50 controlled by the adjustment lever 18 and the adjustment slider 16 is activated when the adjustment spring 24 is suddenly tensioned or when the rotational speed is suddenly reduced.
Suppresses the rapid movement of the base cylinder. As already mentioned, a bidirectional shock absorber makes it possible to change the fuel injection amount with a time delay both when the rotational speed increases and when the rotational speed decreases. . Due to the fact that the shock absorber 50 is coupled to the adjusting lever 18 which is subjected to only a slight force, for example by an idle spring 44 which is suspended stationary relative to the housing, the response time of the shock absorber 50 is limited to a full rotational speed. It remains almost constant over the range.

In the embodiment of the adjusting device shown in FIG. 2, which is constructed and operates substantially the same as the adjusting device of FIG. 1, identical parts have been provided with the same reference numerals as in FIG. This embodiment differs from that of FIG. 1 in the following points. That is, adjustment spring 2
4 is also connected to the adjustment lever 18 to the flexible pull.

For this purpose, a suspension rod 60 is hooked to one end of the adjusting spring 24, which extends through the hole 26 of the lever 22 and, in alignment with this hole 26, through the hole 61 of the adjusting lever 18, and which extends through the head 62. Thus, a soft intermediate spring 64 is held between the spring receiver 63 and the adjustment lever 18 via the spring receiver 63. A stopper disk 27 for the lever 22 is fixed to the shaft portion of the suspension rod 60. Intermediate spring 64 serves to compensate for play between adjusting lever 18 and lever 22.

[Brief explanation of the drawing]

FIG. 1 is a principle illustration of a first embodiment of a fuel injection pump with a regulating device, and FIG. 2 is a partial principle diagram of a second embodiment of a fuel injection pump with a regulating device.

Claims (1)

[Claims] 1. It is a fuel injection pump for an internal combustion engine, and has a delivery amount adjusting member (16) that adjusts the amount of fuel delivered, and a speed regulating mechanism that operates the delivery amount adjusting member (16), and the speed regulating mechanism is It consists of an adjustment lever (18) connected to the delivery amount adjustment member (16), and a lever (22) supported on the same shaft (19) as the adjustment lever (18) and carrying the adjustment lever (18). It has a lever mechanism, which on the one hand has an adjusting spring (2
4) and a centrifugal speed governor (30
), the adjustment spring (2
4) is a lever (
22) and an idling spring (
Fuel injection pump for an internal combustion engine, characterized in that the fuel injection pump (44) has its point of action on a regulating lever (18) which is entrained by said lever (22) which is loaded by a centrifugal governor (30). 2. Idling spring (44) is adjustable member (4)
5) The fuel injection pump according to claim 1, wherein the fuel injection pump is adjustable via 5). 3. In the path of the pivoting movement of the adjusting lever (18), which is loaded by the idling spring (44), an adjustable stop (46) is arranged, which limits said pivoting movement in the direction of increasing the fuel delivery amount; 3. A fuel injection pump according to claim 1, wherein the position of the stopper is determined by operating parameters of the internal combustion engine. 4. 4. A fuel injection pump according to claim 3, wherein said stop (46) is operated by a hydraulic, pneumatic or electric nodal drive (47). 5. A shock absorber (5) is added to the adjustment lever (18).
0) is connected to the fuel injection pump according to any one of claims 1 to 4. 6. The shock absorber (50) is a hydraulic shock absorber piston (5).
2), the piston is loaded with the internal pressure of the fuel injection pump, and the piston has a throttle hole (55) with an overpressure valve (56) connected downstream; A fuel injection pump according to claim 5. 7. 7. Fuel injection pump according to claim 5, wherein the damping device (50) produces a damping effect in both adjustment directions.